1. Field of the Invention
The present invention relates to a floor construction for the upper compartment of an aircraft having a fuselage with approximately circular cross-section, which comprises mainly bending supports supported on their sides by support elements and running cross to the longitudinal of the fuselage.
2. Brief Description of the Background of the Invention Including Prior Art
The inner structure of the fuselage of in particular large capacity aircraft comprises substantially a first floor of an upper loading compartment and a second floor of a lower loading compartment as well as the side walls of the lower load compartment, where in most cases the upper load compartment serves as a space for passengers and the lower load compartment as a space for freight. The upper floor rests on horizontal cross support pieces, which are disposed approximately diametrical within the nearly circular fuselage frame. The ends of the cross support pieces are solidly connected to the web of the fuselage frame in each case for example by way of a rivet. Longitudinal profiles or rails are running above the cross support pieces of in general I-shaped cross-section and are formed with the cross support pieces via braces to a metal frame. Light construction honeycomb plates are inserted as floor elements into the fields of this frame, which consist of fiber reinforced plastic and which are bolted or screwed to the cross support pieces or respectively the longitudinal raisl. For increasing of the bending strength of the cross pieces these are close to their ends supported against the lower part of the fuselage frame in each case. The light construction honeycomb plates consisting of fiber reinforced plastic are screwed or bolted to the support rods serving as support elements, which light construction honeycomb plates form the side walls of the freight compartment. Corresponding light construction honeycomb plates are screwed or bolted from the freight compartment to the floor cross support pieces and thus form the sky of the freight compartment. In principle, the floor of the freight compartment is constructed similar to the floor of the passenger compartment. Based on the integrated loading provisions (ball mats) the floor plates are in part provided as light metal constructions. According to a principle recognizable from the known solutions, the floors of the passenger and of the freight compartment as well as the side walls of the latter are always constructed from supporting and surface forming elements.
Based on the rigid connection of the cross support pieces of the upper floor with the fuselage frame as well as based on its diametral disposition especially this floor is subjected to deformations, which the outer structure experiences based on loads becoming effective during the flight. The static consideration of the forces resulting therefrom is determining in part for the construction weight of the floor construction. Based on the complex formation of the individual construction groups thus fairly high construction costs results.